Novel Lead dioxide-Graphite-Polymer composite anode for electrochemical chlorine generation

Lead dioxide coated graphite powder (G-PbO2) was synthesized using in-situ wet chemical synthesis method. Phase identification by X-ray diffraction (XRD) revealed the successful synthesis of G-PbO2 powder, containing beta-PbO2. This powder was mixed with poly-methyl methacrylate (PMMA) and molded into circular discs for use as electrodes conveniently. The surface morphology and composition of the polymer composite (G-PbO2-PMMA) electrodes was characterized using SEM, EDXA and XPS. Electron transfer dynamics at the G-PbO2-PMMA electrode were examined using standard ferro-ferricyanide redox couple, Fe(CN)(6)(3 /4) , which displayed peak-to-peak separation of similar to 71 mV. The electrochemical evolution of chlorine at G-PbO2-PMMA anode was also studied which showed favorableshift in the value of oxidation peak potential by similar to 116 mV relative to Pt electrode. The concentration of total chlorine in solution was determined as a function of number of cyclic voltammetric scans at different scan rates. The observed concentration of the dissolved Cl-2 was 23 mg L (1) (G-PbO2-PMMA, 5 mVs (1), 50CV cycles) and 15 mg L (1)(Pt, 5 mVs (1), 50CV cycles). The performance of G-PbO2-PMMA with respect to chlorine evolution was found to be better compared with that of Pt electrode. The electron transfer at the lead dioxide coated graphite is found to be facile and the G-PbO2-PMMA is inferred to be good anode material for efficient Cl-2 evolution. (C) 2015 Elsevier Ltd. All rights reserved.